Silicon-based coupling platform for optical fiber switching in free space

This paper presents the novel concept of a silicon-based coupling platform integrated with an electrostatic-driven out-of-plane optical switch, a self-parking framework, a flat-topped mesa, a v-groove and a microball lens array. The electrostatic-driven out-of-plane optical switch consists of a vertical mirror on a suspension polyimide diaphragm. It can reduce the large motion space required in in-plane optical switches. The method of corner compensation with the help of IntelliCAD software was applied to design the self-parking framework and flat-topped mesa. These were fabricated at the same time by the anisotropic wet etching technique. The microball lens array was batch-fabricated with the microelectromechanical systems technique and batch-assembled onto the coupling platform. The design of the optical platform is able to control the distance between the fiber, the microball lens and the vertical mirror. Therefore, it can enhance the coupling efficiency. Furthermore, not only does it provide an accurate coupling distance, but also it reduces the cost of the micro-assemblage.